Screw cap for a portable electronic device

ABSTRACT

A screw cap for covering a head of a screw in a screw hole ( 20 ) of a housing ( 2 ) of a portable electronic device. The screw hole includes a wide upper portion ( 202 ) and a narrow lower portion ( 204 ). The screw cap includes a main body ( 12 ) and an elastic ring ( 14 ). The main body includes a wide head ( 122 ) and an adjoining narrow cylindrical body ( 124 ). An upper first groove ( 1242 ) and a lower second groove ( 1243 ) are defined in the cylindrical body. The first groove is deeper than the second groove. When the elastic ring is engaged in the second groove, the screw cap can be interferentially engaged in the screw hole. When the screw cap is pushed so that the elastic ring is engaged in the first groove, the screw cap can be easily removed from the screw hole.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to screw caps that cover headsof screws, and more particularly to screw caps for portable electronicdevices. The invention relates to a contemporarily filed applicationtitled “EXPANDABLE SCREW COVER” and having the same assignee with theinstant invention.

2. Prior Art

Nowadays, major parts of a portable electronic device such as a mobilephone are generally attached together with screws. Where one of theparts is the housing of the mobile phone, the head of each screw isconventionally exposed at an outer surface of the housing. This detractsfrom the aesthetic appearance of the mobile phone. Therefore in morerecent times, manufacturers have configured a motherboard to be attachedto a first half-shell of a housing of the mobile phone with screws, witha second half-shell of the housing being attached to the firsthalf-shell by other means such as snap-fitting. In this way, the headsof the screws are hidden within the housing. For example, ERICSSON'smobile phone model no. T68 adopts the above-mentioned newer type ofsecuring means.

However, assembly of the above-mentioned new kind of portable electronicdevice is much more complicated than assembly of the more conventional,less aesthetic type of portable electronic device. Therefore, some modemportable electronic devices still adopt securing of an upper cover to alower cover thereof with screws. In addition, a cylindrical cap made ofsoft plastic is engaged in each screw hole so that it covers the screwhead. The diameter of the cap is slightly larger than the diameter ofthe screw hole, so that the cap interferentially fits in the screw holeand does not fall out. For example, SAMSUNG's mobile phone model no.N188 adopts this type of aesthetic securing means. However, indisassembly, a hard, sharp tool needs to be inserted between the cap andthe housing. The caps have to be removed from the housing one by one,which is very laborious. Moreover, because the caps are made of softplastic, they are easily damaged and distorted during normal use of theportable electronic device. This not only reduces their aestheticappearance, but can also make disassembly more difficult andinconvenient.

Therefore, a screw cap for a portable electronic device which overcomesthe above-described disadvantages is desired.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide a screwcap for a portable electronic device which enables the portableelectronic device to be conveniently assembled and disassembled.

To achieve the above-mentioned object, a screw cap for a portableelectronic device of the present invention comprises a main body and anelastic ring. The main body comprises a head located a top thereof, anda cylindrical body adjoining a bottom of the head. An outer diameter ofthe cylindrical body is less than an outer diameter of the head. A firstgroove and a second groove are defined in circumferential surface of thecylindrical body. The first groove is near a top of the cylindricalbody, and is deeper than the second groove. When the elastic ring isengaged in the second groove, the screw cap can be interferentiallyengaged in a screw hole of a housing of the portable electronic device.When the screw cap is pushed so that the elastic ring is engaged in thefirst groove, the screw cap can be easily removed from the screw hole.

Other objects, advantages and novel features of the invention willbecome more apparent from the following detailed description when takenin conjunction with the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded, isometric view of a screw cap of a portableelectronic device in accordance with a preferred embodiment of thepresent invention;

FIG. 2 is an isometric, cut-away view of part of a housing of a portableelectronic device that utilizes the screw cap of FIG. 1;

FIG. 3 is similar to FIG. 2, but showing the screw cap of FIG. 1attached in the housing in a first position; and

FIG. 4 is similar to FIG. 3, but showing the screw cap accommodated inthe housing in a second position.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, a screw cap of a portable electronic device inaccordance with the preferred embodiment of the present inventioncomprises a main body 12 and an elastic ring 14 that has a gap (notlabeled) therein. The main body 12 includes a head 122 and a cylindricalbody 124. The head 122 is located at the top of the main body 12, withthe cylindrical body 124 adjoining a bottom of the head 122. The head122 and the cylindrical body 124 can be integrally formed together atthe same time. An outer diameter of the cylindrical body 124 is lessthan an outer diameter of the head 122. An upper first groove 1242 and alower second groove 1243 are respectively defined in a circumferentialsurface of the cylindrical body 124. The first groove 1242 is near a topof the cylindrical body 124, and is deeper than the second groove 1243.A stop block 1244 is formed on the cylindrical body 124. The stop block1244 protrudes from the circumferential surface of the cylindrical body124 below the second groove 1243. The elastic ring 14 can be engaged inthe first groove 1242 or the second groove 1243, and can be taken outfrom the first or second grooves 1242, 1243 by manipulating the elasticring 14 at the gap thereof. When the elastic ring 14 is engaged in thesecond groove 1243, an outer diameter of the elastic ring 14 is greaterthan the diameter of the head 122. When the elastic ring 14 is engagedin the first groove 1242, the outer diameter of the elastic ring 14 isless than the diameter of the head 122.

Referring to FIG. 2, the portable electronic device utilizing the screwcap comprises a housing 2, and a screw hole 20 defined in the housing 2.The screw hole 20 is stepped, and thereby comprises an upper portion 202and a lower portion 204. A diameter of the upper portion 202 is greaterthan a diameter of the lower portion 204. The diameter of the upperportion 202 is slightly greater than the diameter of the head 122, sothat the head 122 can be fittingly received in the upper portion 202.The diameter of the lower portion 204 is slightly greater than thediameter of the cylindrical body 124, so that the cylindrical body 124can be fittingly received in the lower portion 204. An annularsupporting step 206 is defined at the junction of the upper portion 202and the lower portion 204. A vertical sliding groove 207 is defined inan inner wall of the housing 2 at the lower portion 204, with a topextremity of the sliding groove 207 being at the supporting step 206. Astop step 208 is defined at a bottom of the sliding groove 207. The stopblock 1244 of the cylindrical body 124 can slide in the sliding groove207 and can be stopped by the stop step 208. In addition, the outerdiameter of the elastic ring 14 in an uncompressed state in the secondgroove 1243 is slightly greater than the diameter of the upper portion202.

Referring also to FIG. 3, in assembly, a screw (not shown) is mounted inthe screw hole 20 of the housing 2. The elastic ring 14 is invaginatedinto the second groove 1243 of the main body 12. The screw cap is theninserted into the screw hole 20. The head 122 is pressed down. The mainbody 12 slides into the screw hole 20, with the elastic ring 14interferentially sliding down along the upper portion 202, and the stopblock 1244 sliding down in the sliding groove 207. The head 122 is thuspressed until a top face thereof is level with or lower than a top faceof the housing 2. This position can be attained because a distancebetween the second groove 1243 and the top face of the head 122 is lessthan a depth of the upper portion 202 of the screw hole 20. In addition,because the outer diameter of the elastic ring 14 in the uncompressedstate in the second groove 1243 is slightly greater than the diameter ofthe upper portion 202, the screw cap is tightly fixed in the screw hole20.

Referring to FIG. 4, in disassembly, the head 122 is pressed down. Theelastic ring 14 slides with the main body 12 in the upper portion 202toward the supporting step 206. Because the outer diameter of theelastic ring 14 in the second groove 1243 is greater than the diameterof the lower portion 204 of the screw hole 20, the elastic ring 14 isstopped by the supporting step 206. When the head 122 is continued to bepressed, the cylindrical body 124 interferentially slides down throughthe elastic ring 14. Thus the elastic ring 14 is disengaged from thesecond groove 1243, and moves relative to the cylindrical body 124 untilit eventually engages in the first groove 1242. In this position,because the outer diameter of the elastic ring 14 in the first groove1242 is less than the diameter of the head 122, the screw cap is in nolonger tightly fixed in the screw hole 20. The portable electronicdevice is then inverted, so that the screw cap drops out from the screwhole 20.

It is believed that the present invention and its advantages will beunderstood from the foregoing description, and it will be apparent thatvarious changes may be made thereto without departing from the spiritand scope of the invention or sacrificing all of its materialadvantages. The examples hereinbefore described are merely preferred orexemplary embodiments of the invention.

1. A screw cap for a portable electronic device, comprising: a main bodycomprising a head and a cylindrical body, the head being located at atop of the main body, the cylindrical body adjoining a bottom of thehead, a diameter of the cylindrical body being less than a diameter ofthe head, the cylindrical body defining a first groove and a secondgroove in a circumferential surface thereof, the first groove being at atop of the cylindrical body and being deeper than the second groove; andan elastic ring; wherein said elastic ring is engagable in the firstgroove or the second groove.
 2. The screw cap as claimed in claim 1,wherein an outer diameter of said elastic ring is greater than thediameter of the head when said elastic ring is engaged in the secondgroove.
 3. The screw cap as claimed in claim 2, wherein an outerdiameter of said elastic ring is less than the diameter of the head whensaid elastic ring is engaged in the first groove.
 4. The screw cap asclaimed in claim 3, wherein a gap is defined in said elastic ring. 5.The screw cap as claimed in claim 4, wherein a stop block is formed onthe cylindrical body.
 6. A portable electronic device comprising: ahousing defining a screw hole therein, the screw hole including an upperportion and a lower portion, a diameter of the upper portion beinggreater than a diameter of the lower portion; and a screw capcomprising: a main body comprising a head and a cylindrical body, thehead being located at a top of the main body, the cylindrical bodyadjoining a bottom of the head, a diameter of the cylindrical body beingless than a diameter of the head, the cylindrical body defining a firstgroove and a second groove in a circumferential surface thereof, thefirst groove being at a top of the cylindrical body and being deeperthan the second groove; and an elastic ring; wherein the screw cap canbe interferentially engaged in the screw hole when the elastic ring isengaged in the second groove, and the screw cap can benon-interferentially accommodated in the screw hole when the elasticring is engaged in the first groove.
 7. The portable electronic deviceas claimed in claim 6, wherein a stop member is provided at thecircumferential surface of the cylindrical body.
 8. The portableelectronic device as claimed in claim 7, wherein the housing defines asupporting step at a junction of the upper portion and the lowerportion.
 9. The portable electronic device as claimed in claim 8,wherein a sliding groove is defined in an inner wall of the housing atthe lower portion.
 10. The portable electronic device as claimed inclaim 9, wherein the housing defines a stop step at a bottom of saidsliding groove.
 11. The portable electronic device as claimed in claim10, wherein a top extremity of said sliding groove is at said supportingstep.
 12. A combination of a screw cover structure comprising: a holeextending inwardly from a surface; a screw cap disposed in the hole andincluding: a main body; and an auxiliary piece moveable relative to themain body along an axial direction of the hole, and selectively retainedat first and second positions of said main body; wherein when saidauxiliary piece is located in the first position, the auxiliary piece isurged by the main body to retainably engage an interior surface of thehole so as to retain the screw cap in a hole and be flush with thesurface; when the auxiliary piece is move from the first position to thesecond position, the auxiliary piece is no longer retainably engagedwith the interior surface of the hole so as to allow the screw cap to beremoved from the hole.
 12. The combination as claimed in claim 11,wherein said main body provides a diametrical dimension fully coveringthe hole
 13. The combination as claimed in claim 11, wherein saidauxiliary piece is a ring attached to a periphery of said main body. 14.The combination as claimed in claim 13, wherein said main body definestwo grooves to receive said ring when said ring is located in the firstand second positions, respectively.
 15. The combination as claimed inclaim 14, wherein said tow grooves have different depths.
 16. Thecombination as claimed in claim 11, wherein when said auxiliary piece ismoved from the first position to the second position, said main body,rather than the auxiliary piece, is moved in the axial direction alongthe hole.